Polyploidy and apomixis in the Casuarina distyla species group

1959 ◽  
Vol 7 (3) ◽  
pp. 238 ◽  
Author(s):  
BA Barlow
Keyword(s):  
Breeding System ◽  
Related Species ◽  
Genetic System ◽  
Species Group ◽  
The Other ◽  
Diploid Population ◽  
Closely Related Species ◽  
Triploid Plant

In the Casuarina distyla species group, which includes 13 closely related species, sexual tetraploid forms have been recorded in nine species and apomictic triploids in four. These forms are probably autopolyploids. The triploid apomiots are presumably diplosporous and parthenogenetic, and in two species are pseudogamous, but not in the other two. It is suggested that a transition from the former to the latter breeding system would follow elimination of the need for pseudogamy. A hypothesis is presented that polyploidy and apomixis have arisen together within the species through establishment in a diploid population of a triploid plant which is diplosporous and parthenogenetic. The genetic system involved probably spread through the group during the evolution of the species, giving them a potential for this kind of development.

Pimpinella ibradiensis (Apiaceae), an unusual new species from Turkey

Phytotaxa ◽  
2015 ◽  
Vol 217 (2) ◽  
pp. 164 ◽  
Author(s):  
İlker Çinbilgel ◽  
özkan Eren ◽  
Hayri Duman ◽  
Mustafa Gökceoğlu
Keyword(s):  
New Species ◽  
Geographical Distribution ◽  
Related Species ◽  
Conservation Status ◽  
Identification Key ◽  
The Other ◽  
Site Conditions ◽  
Closely Related Species

Pimpinella ibradiensis, an unusual new species found in the Toka Yayla (İbradı, Antalya) in southern Anatolia, is described and illustrated. Site conditions, synecology and conservation status of P. ibradiensis are considered. In light of the comparison with the other closely related four species, namely P. nephrophylla, P. flabellifolia, P. sintenisii and P. paucidentata, its similarity within the genus are discussed. P. ibradiensis is easly distinguished from its relatives by its white petals, presence of bracts and bracteoles, larger fruits (4–5.5 × 1–2 mm), and having serrulate basal leaves with 60–95 strongly cartilaginous teeth along margins. The geographical distribution of P. ibradiensis and closely related species are mapped and the identification key of those species is updated.

scholarly journals Repeated evolution of asymmetric genitalia and right-sided mating behavior in theDrosophila nannopteraspecies group

2019 ◽  
Author(s):  
Andrea Acurio ◽  
Flor T. Rhebergen ◽  
Sarah Paulus ◽  
Virginie Courtier-Orgogozo ◽  
Michael Lang
Keyword(s):  
Related Species ◽  
Current Data ◽  
The Other ◽  
Genital Morphology ◽  
Closely Related Species ◽  
Outgroup Species ◽  
Repeated Evolution ◽  
Drosophila Pachea ◽  
Species Specific ◽  
Group Species

AbstractBackgroundMale genitals have repeatedly evolved left-right asymmetries, and the causes of such evolution remain unclear. TheDrosophila nannopteragroup contains four species, among which three exhibit left-right asymmetries of distinct genital organs. In the most studied species,Drosophila pachea, males display asymmetric genital lobes and they mate right-sided on top of the female. Copulation position of the other species is unknown.ResultsTo assess whether the evolution of genital asymmetry could be linked to the evolution of one-sided mating, we examined phallus morphology and copulation position inD. pacheaand closely related species. The phallus was found to be symmetric in all investigated species exceptD. pachea, which display an asymmetric phallus with a right-sided gonopore, andD. acanthoptera, which harbor an asymmetrically bent phallus. In all examined species, males were found to position themselves symmetrically on top of the female, except inD. pacheaandD. nannoptera, where males mated right-sided, in distinctive, species-specific positions. In addition, the copulation duration was found to be increased innannopteragroup species compared to closely related outgroup species.ConclusionOur study shows that gains, and possibly losses, of asymmetry in genital morphology and mating position have evolved repeatedly in thenannopteragroup. Current data does not allow us to conclude whether genital asymmetry has evolved in response to changes in mating position, or vice versa.

scholarly journals On the Species of the Dugesia Gonocephala Group (Platyhelminthes, Turbellaria, Tricladida) from Greece

1984 ◽  
Vol 54 (1) ◽  
pp. 101-126 ◽  
Author(s):  
Elizabeth J. de Vries
Keyword(s):  
New Species ◽  
Related Species ◽  
Mediterranean Region ◽  
Eastern Mediterranean ◽  
Eastern Mediterranean Region ◽  
Species Group ◽  
Closely Related Species ◽  
Dugesia Gonocephala Group

Dugesia gonocephala is a species group, comprising numerous closely related species, which differ from each other in morphological and karyological aspects. In this paper known and presently described species, of the group from the eastern Mediterranean region, are reviewed. Hitherto the triclads of this region have been poorly known in comparison with their western counterparts. Yet there is a wealth of species in the area. Six well-delimited new species of the Dugesia gonocephala group are described and one further species is rescued from synonymy. The wealth of material available has also made possible an assessment of the taxonomic validity of many characters usually considered to be of importance within this difficult group.

scholarly journals A NEW ANTHAXIA FROM THE AEOLIAN ISLANDS (COLEOPTERA, BUPRESTIDAE)

2010 ◽  
Vol 42 (2) ◽  
pp. 499
Author(s):  
Pietro Lo Cascio ◽  
Ignazio Sparacio
Keyword(s):  
New Species ◽  
Related Species ◽  
Body Shape ◽  
Species Group ◽  
Colour Pattern ◽  
Closely Related Species ◽  
Aeolian Islands ◽  
Endemic Taxon

<em>Anthaxia</em> (<em>Haplanthaxia</em>) <em>flaviae</em> n. sp. from the Aeolian Islands (Italy, Sicily) belonging to the <em>A</em>. (<em>H</em>.) <em>olympica</em> Kiesenwetter, 1880 species-group is described, illustrated and compared with <em>A</em>. (<em>H</em>.) <em>scutellaris</em> (Gené, 1839), the most closely related species. From this latter, the new species differs mainly for size and body shape, colour pattern of elytrae, shape of antennomera, margin of anterior tibiae and shape of aedeagus. Some zoogeographical considerations concerning the insular distribution of this endemic taxon are briefly discussed.

A giant Permian fusulinid from east-central Alaska with comparisons of all giant fusulinids in western North America

1995 ◽  
Vol 69 (5) ◽  
pp. 805-812 ◽  
Author(s):  
Calvin H. Stevens
Keyword(s):  
North America ◽  
Related Species ◽  
The Other ◽  
Lower Permian ◽  
Early Permian ◽  
Western North America ◽  
Closely Related Species ◽  
East Central ◽  
West Texas ◽  
Species Groups

The discovery of a new locality yielding giant Guadalupian (Lower Permian) fusulinids in east-central Alaska extends the range of these forms much farther north than previously known, and into a tectonostratigraphic terrane from which they previously had not been reported. The number of areas from which giant parafusulinids are known in North America is thus raised to eight. Three of these localities are in rocks that previously had been referred to the allochthonous McCloud belt arc, and one, West Texas, is known to have been part of Paleozoic North America. Comparison of species from all areas suggests that there are two closely related species groups: one represented in Texas and Coahuila, and the other represented in Sonora, northern California, northeastern Washington, southern and northern British Columbia, Alaska, and apparently in Texas. These groups may differ because they are of slightly different ages or because interchange between the faunas of Texas–Coahuila area and the other regions was somewhat inhibited during the Early Permian.

scholarly journals Genetic analyses of several Drosophila ananassae-complex species show a low-frequency major gene for parthenogenesis that maps to chromosome 2

2004 ◽  
Vol 83 (2) ◽  
pp. 83-89 ◽  
Author(s):  
MUNEO MATSUDA ◽  
YOSHIKO N. TOBARI
Keyword(s):  
Related Species ◽  
Genetic Basis ◽  
Present Report ◽  
Major Gene ◽  
American Samoa ◽  
Species Group ◽  
Drosophila Ananassae ◽  
Chromosome 2 ◽  
Closely Related Species ◽  
Complex Species

Parthenogenetic strains of several species have been found in the genus Drosophila. The mode of diploidization in the eggs of females has been found to be post-meiotic nuclear fusion. The genetic basis for this parthenogenesis is not understood but is believed to be under the control of a complex polygenic system. We found parthenogenetic females in an isofemale strain (LAE345) of D. pallidosa-like collected in 1981 at Lae, Papua New Guinea, and established a parthenogenetically reproducing strain. Parthenogenetic strains of D. ananassae and D. pallidosa collected at Taputimu, American Samoa had also been established by Futch (1972). D. ananassae, D. pallidosa and D. pallidosa-like are very closely related species belonging to the ananassae complex of the ananassae species subgroup of the melanogaster species group. Using these three species, we found that more than 80% of females from parthenogenetic strains produced progeny parthenogenetically and that inter-specific hybrid females also produced impaternate progeny. In the present report, we demonstrate that the mode of parthenogenesis of D. ananassae appears to be the post-meiotic nuclear doubling of a single meiotic product, and that a major gene responsible for the parthenogenesis maps to the left arm of the second chromosome of D. ananassae. We also suggest that the genetic basis for parthenogenesis capacity may be identical among the three closely related species. We discuss the function of the gene required for parthenogenesis and its significance for the evolutionary process.

scholarly journals A New Species of Ligyrocoris Stal With a Key to the Northeastern Species (Hemiptera:Lygaeidae)

1963 ◽  
Vol 70 (1) ◽  
pp. 17-21
Author(s):  
Merrill H. Sweet
Keyword(s):  
New Species ◽  
Life Cycle ◽  
New England ◽  
Related Species ◽  
Habitat Preferences ◽  
Life Cycles ◽  
The Other ◽  
Closely Related Species ◽  
Carex Stricta ◽  
A New Species

In the course of current work upon the biology and ecology of the Rhyparochrominae of New England, a new species of Ligyrocoris was discovered. The species runs in Barber's (1921) key to the couplet separating diffusus (Uhler) from sylvestris (L.), but is distinct from either species. While the new species is closely related to these species, it is also quite close to L. depictus which is separated out in a different part of Barber's key.These four closely related species are sympatric in New England, although they are markedly different in their overall distribution. The habitat preferences and life cycles of the species are quite different (Sweet, unpublished). The habitat of the new species described below is most unusual for the genus. The greater part of the type series was collected along the margin of a small pond where sedge clumps were standing in the water among occasional exposed rocks rather than in relatively dry fields or slope habitats where the other species occur. The species feeds upon the seeds of the sedge, Carex stricta Lam, and its life cycle is apparently adapted to that of the sedge, which fruits in late May and June. The insect becomes adult in mid-June and lays eggs until mid-July. The eggs remain in diapause over the summer and winter and hatch in May.

A NEW SPECIES OF THE PERILISSUS ANATINUS SPECIES GROUP AND NOTES ON THE RELATIONSHIPS OF THE SPECIES GROUPS OF PERILISSUS (HYMENOPTERA, ICHNEUMONIDAE, CTENOPELMATINAE)

1994 ◽  
Vol 126 (2) ◽  
pp. 219-224 ◽  
Author(s):  
John Barron
Keyword(s):  
Species Group ◽  
Included Study ◽  
The Other ◽  
Southern Mexico ◽  
Closely Related Species ◽  
Mountain Ranges ◽  
Species Groups ◽  
Relationship Of ◽  
The Relationship ◽  
A New Species

AbstractIndividuals of Perilissus nudus sp.nov. of the Perilissus anatinus species group are described. This species, which occurs in the mountain ranges of southern Mexico and Costa Rica, is compared with the closely related species P. anatinus Barron. Locality data on additional specimens of P. anatinus, found in mountain ranges in Mexico, are included. Study of characteristics of P. nudus in relation to P. anatinus clarifies further the relationship of this species group with the other species groups of Perilissus.

Systematics of the Adiantum philippense complex (Pteridaceae, Polypodiales) in Taiwan

Phytotaxa ◽  
2016 ◽  
Vol 263 (2) ◽  
pp. 113 ◽  
Author(s):  
LI-YAUNG KUO ◽  
TIAN-CHUAN HSU ◽  
YI-HAN CHANG ◽  
YAO-MOAN HUANG ◽  
WEN-LIANG CHIOU
Keyword(s):  
Cryptic Species ◽  
Related Species ◽  
Species Complex ◽  
The Other ◽  
Closely Related Species ◽  
Hybrid Combination ◽  
Reproductive Modes ◽  
Taxonomical Revision

Adiantum philippense s.l. is a member of once-pinnate Adiantum but comprise several cytotaxa with different ploidies and reproductive modes. According to the differences of cytotypes, the up-to-date revision had identified three subspecies under the A. philippense complex. In Taiwan, different ploidies and reproductive modes had also been found in this species complex, and existence of (a) cryptic species among these cytotypes had been suggested. The current study focuses on taxonomical revision of Taiwanese A. philippense complex. We sampled not only different Taiwanese cytotypes/populations but also all subspecies under A. philippense and the closely related species of them. By re-examining their phylogeny, ploidies, and reproductive modes, we confirmed that the sexual diploids in Taiwan belong to Adiantum menglianense, and this species is phylogenetically separated from A. philippense. We further approved that A. menglianense can be morphologically distinguished from A. philippense by their frond features and spore numbers in sporangia. Another taxon of Taiwanese A. philippense complex is A. philippense subsp. philippense, which is an apomictic and triploidy subspecies. Additionally, we assigned lectotypes of A. menglianense, and revised the hybrid combination of A. × meishanianum. We also provided a key in order to identify two taxa under Taiwanese A. philippense complex and the other once-pinnate Adiantum species in Taiwan.

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